This looks like a duplicate of your reply at gis.stackexchange.com/a/12513. It's best for a reply to live in just one location (you can always link to it from another). If you want to keep this one, then please take to heart the comment below the other one and look at its source to see how you can use the img tag to shrink these screenshots.
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whuber♦Mar 30 '12 at 22:27

CyberTracker is the most efficient method of field data collection.
You can use CyberTracker on a Smartphone or handheld computer to
record any type of observation. CyberTracker, which requires no
programming skills, allows you to customize an Application for your
own data collection needs.

Only supports PalmOS, PocketPC and Windows Mobile devices right now thought. Since January 2013, it's working on Android devices too.

MapItFast from AgTerra Technologies (www.agterra.com) is worth a look. The product only works on Android devices at this time but they offer real time mapping, attribution with electronic forms, and sync to a private cloud account. It works with or without a data connection in the field. Basemaps, custom layers and export to shapefile, KMZ, and GPX is included. Good way for field workers to gather spatial data for GIS professionals and it could be used as a low cost asset management system.

More to inform people which can be interested, here: carnet-terrain-electronique, a website devoted to mobile data collection, especialy for environmental data, avec some links for devices, apps, advices... don't hesitate to propose more things.

Unfortunately, this website is in french but it has a GTranslate module.

GeoODK provides a way to collect and store geo-referenced information, along with a suite of tools to visualize, analyze and manipulate ground data for specific needs. It enables an understanding of the data for decision-making, research, business, disaster management, agriculture and more. As a multi-dimensional application, GeoODK’s goal is to provide an open source platform that can be expanded to address current and future needs of data collection.

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.
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R.K.Dec 1 '14 at 16:03

The LatLonGO® solution has been designed from first principles to address the challenges faced by mobile GIS today.

It provides the end-user with a system for distributing GIS information seamlessly to any touch client mobile device (iPad, Android and Windows 8 tablets). LatLonGO® compresses, encrypts and distributes data for mobile tablet devices, allowing users to work on-line or offline without network access.

It can process data from any GIS format and serve it from any in-house or external (cloud) server. LatLonGO® is ideal for mobile workers who require access to their corporate GIS data any time, even in remote or security sensitive locations where no web access is allowed. It provides an up-to-date copy of corporate data and handles Smallworld GIS, ESRI ArcGIS and SPATIALinfo spatialNET natively (WYSIWYG) and any other GIS format via OpenGeo or FME.

The LatLonGO® mobility solution is a powerful geo-centric mobile integration platform to any other enterprise information system.